Bad roofs - no one enters into the reroofing process with this goal in mind. A failed roof causes unproductive conflict, causes damage to building interiors and contents, and often ends up in the legal system. So why do bad roofs happen to good people?

Clearly there are few building owners that would knowingly buy a bad roof. Yet we inspect roofs every day that should not have been, roofs that fail because of poor material selection or are inappropriate for the particular site or location. Bad roofs can result from a disregard of the building's use, or a few poorly conceived details.

While shoddy workmanship or poor quality materials often get the blame for a poor quality roof, the die is cast when a reroofing project starts from a poor roof design. No level of installer's skill or superior physical properties of the roofing material will change the result.

Good roof design includes providing specific solutions to problem details. Finally, good roof design requires a document that translates these design decisions into a set of instructions for the roofing contractor to follow.

Architects, engineers, contractors, roofing suppliers, roof consultants and building owners are all possible suspects when it comes to roof design. The point is, even on the simplest project, someone has to make roof design decisions.

Any of these "suspects" may have the education, knowledge and experience to make good design decisions. However, the motivations of the designer may influence the appropriateness of the design.

Leave it to a roof consultant to infer there is something wrong with roofers and manufacturers designing roofs. As self-serving as that sounds, there is logic to it.

Roofing contractors make their living installing roofs. They have built their businesses by training their roofers in specific roofing materials. They have established key relationships with their suppliers, have invested in specialized equipment, and so, there may be motives other than choosing the best roof for the specific project.

The desire to "win" a project can cause the roofing contractor / designer to exploit competitive advantages he has over other bidders, and sometimes compromise the design.

Manufacturers or suppliers may also have blinders on when it comes to providing the optimum roof design solution. As most manufacturers provide no cost or low cost roof design services, they are not likely to recommend a product or system they do not offer. They are also not likely to specify competitor's products to create a competitive bidding environment. They are, after all, in the business of selling their products.

In the end, contractors and manufacturers are conflicted by self-interest. If the goal in a reroofing project is to have the optimum roof system, proper design and good documentation, then an independent roof designer should be considered.

The cost of roof design / bid services is generally dependent more on the complexity of the project as opposed to shear size. Highly complex projects that require multiple roof assemblies, more detail drawings, etc., should be expected to cost more then less complex projects.

Fixed fee, time-and-expense, and fee as a percentage of construction cost are all methods of establishing a cost for design services. While there are arguments for all three methods, I have never understood the practice of establishing the designer's fee based on a percentage of the lowest bid. Fixed fee or T&E are most often used.

Design fees can vary from 20% of the contract price for small complex projects to 2% for less involved larger projects. A more common average would be in the 5% to 8% range.

Well-conceived, concise specifications provide an even playing field for bidding contractors. Their confidence that the design will not be changed by other bidders allows them to focus on how to do the project at the lowest cost. Manufacturers appreciate their products being listed beside similar quality competitors, giving each an opportunity to get the project. Fair competition fosters lower costs, without cheapening the roof design.

When contemplating a reroofing project, start with a good plan. The value of the good plan will exceed its cost many times over.